package vip.zhenzicheng.nettybasic.splicing.fixed;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.FixedLengthFrameDecoder;

import java.net.InetSocketAddress;

/**
 * @author zhenzicheng
 * @date 2022-06-24 09:26
 */
public class FixedLengthEchoServer {

  public static final String RESPONSE = "Welcome to Netty!";
  public static final int PORT = 9996;

  public static void main(String[] args) throws InterruptedException {
    FixedLengthEchoServer fixedLengthEchoServer = new FixedLengthEchoServer();
    System.out.println("服务器即将启动");
    fixedLengthEchoServer.start();
  }

  public void start() throws InterruptedException {
    final FixedLengthServerHandler serverHandler = new FixedLengthServerHandler();
    EventLoopGroup group = new NioEventLoopGroup();/*线程组*/
    try {
      ServerBootstrap b = new ServerBootstrap();
      b.group(group)
          .channel(NioServerSocketChannel.class)
          .localAddress(new InetSocketAddress(PORT))
          .childHandler(new ChannelInitializerImp());
      ChannelFuture f = b.bind().sync();/*异步绑定到服务器，sync()会阻塞直到完成*/
      System.out.println("服务器启动完成，等待客户端的连接和数据.....");
      f.channel().closeFuture().sync();/*阻塞直到服务器的channel关闭*/
    } finally {
      group.shutdownGracefully().sync();/*优雅关闭线程组*/
    }
  }

  private static class ChannelInitializerImp extends ChannelInitializer<Channel> {

    @Override
    protected void initChannel(Channel ch) throws Exception {
      ch.pipeline().addLast(
          new FixedLengthFrameDecoder(
              FixedLengthEchoClient.REQUEST.length()));
      ch.pipeline().addLast(new FixedLengthServerHandler());
    }
  }

}
